The glycerolysis reaction of soybean oil was evaluated using crude glycerol obtained from the transesterification of soybean oil with methanol, catalyzed by sodium methoxide and sodium hydroxide, without any purification step other than the methanol removal. Crude glycerol with the lower content of remaining inorganic catalyst produced the highest concentration of monoglycerides (about 42%). The effect of the addition of water on the glycerolysis reaction was analyzed, evidencing a low formation rate of products in the first stages of the reaction due to the transformation of the inorganic catalyst to soaps, which are weaker bases. The sample of crude glycerol that led to the best results was evaluated at several temperatures. It was observed that the reaction with crude glycerol exhibits a lower formation rate of monoglycerides at low temperatures (160 and 180°C) compared with the reaction with pure glycerol and catalyzed with NaOH. This behavior was explained by the lower activity of the soaps present in the crude glycerol respect to the inorganic base. Above 200°C the reaction is very fast and the monoglycerides formed are consumed to produce diglycerides.

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BACKGROUND: Cyclic fatty carbonates can be obtained from epoxidized vegetable oils and CO 2 under mild conditions. The main application of these bio-derivatives is the production of thermoset polymers and non-isocyanate polyurethanes. Castor oil has a different chemical structure from the other oils that have been used for carbonation. In this work, a kinetic model was developed for high CO 2 pressure carbonation of epoxidized castor oil. RESULTS:The highest epoxide group conversion (93%) was obtained at 130 ∘ C and 480 min. However, the highest content of carbonate groups (1.5 carbonates/molecule) was obtained at 115 ∘ C and 180 min. A kinetic model was proposed which included carbonation of epoxide as well as etherification of the oxirane ring as a competitive reaction. Both reactions were best fitted to pseudo-first-order kinetics. Activation energy of carbonation and etherification of the oxirane ring were estimated as 37.41 and 33.25 kJ mol −1 , respectively. CONCLUSION: Carbonated castor oil was produced from the epoxidized oil at 100-130 ∘ C and a constant pressure of CO 2 (0.5 MPa). Because of the polyfunctional character of the product, it could find applications as a monomer and as a synthetic building block for other bio-based chemicals. This product and the reaction pathway have not previously been disclosed.